How long are folks ridding around with their new setup before taking the saw to their steerer tube? Figuring 300 miles or so would give me enough road time.

CT

When you are confident about your setup and fit.

Also, you should be sure you won't be selling it, as it may hurt resale value.

Down periscope!

If we are talking about a carbon steerer (I will confine my remarks to that), it is not usually appropriate to cut the steerer tube all the way to 2-3 mm below the stem top however. Many if not most stem and fork makers these days recommend leaving a 5 mm spacer ABOVE the stem. That assures that the stem clamp grips the steerer somewhat below the open top and crushing the steerer is less likely. If things are set up properly, the top of the steerer will be about 2-3 mm above the top of the stem. Then when you put the 5 mm spacer on, the steerer will sit about 3-2 mm below the top of the spacer. As long as the top cap sits fully above the top of the steerer and can pull up on the steerer, all is good. Then I also like the look. Be sure to allow for that when you do decide to cut the steerer. If the expander has a lip that sits on top of the steerer, be sure to allow for its height when figuring everything out.

Two stages. First after a shakedown so it is not dangerously long, leaving an extra 2-3cm, then a final cut after a couple months having not changed anything. Never leave less than 1cm of spacers, either above or below the stem, or risk having to buy a new fork to fit a new stem or headset.

^ yeah but that's not what OP is asking.

(referring to post #3 about leaving a few mm above stem)

Sure, you are right. I thought your answer said it all in response to the question. What, a two post thread, and then it's done? So I was just taking the opportunity to expand the topic a little with additional good advice.

Oh ok.

Plus, a little closer to 10K?

You got that right.

i usually tell myself i don't care that the steering is sticking up too far, but after a ride or two i always end up with my hacksaw in my hand and carbon dust on my face and a steerer tube 2-3mm below the cap.

I did about 3 rides with new new set-up, this being I had 5 little spacer so I could play around with the positioning. I tried slammed, but did not quite like it at the time, rode with 2 spacers below, and liked that a lot more. I cut it so I could have 2 spacers of play, now I run 1 above and 1 below the stem. I could cut it again, but the weight savings and aesthetic appeal is a minimal gain for the second cut.

Summary: 3 rides with a set-up that I could cut more if I needed to.

This is the best advice.

Last two times I cut mine down I ended up selling the bike/frame about six months later. Make sure you really plan on keeping it especially if you cut it to slam the stem. Negotiating the sale any smart buyer is going to say they are going to need to buy a new fork to drive your price down.

As far as spacers above and below, most frame and fork manufacturer have specific rules especially for full carbon. Read the instructions. I've seen some say leave spacer below, above or both but it's best to listen to the manufacturer unless you want to buy a new fork

whats wrong with leaving a 10mm or so above the stem?

10 is probably okay. 5 is usually thought ideal. A really tall section above the stem is thought to be a safety hazard, however. Besides looking funky.

i have 2.5 above.

As said above, different manufacturers recommend differently depending upon the design and position of their expander and what is required to protect the top edge of the carbon steerer tube from damage. Of course aluminum steerers have no issue. I have concluded that a little steerer above the stem can't ever hurt, and I have actually come to like the look.

i prefer the look of a small amount above. flush with the top looks goofy.

they cut our umbilical cords flush for a good reason.

The expander plug might not reach down far enough to support the steerer against the lower stem bolt.

Slam it... it's the only way

op asked when. not how.

+1

Cutting the steerer is like the difference between dating and getting married. You cut it if and when you're ready to commit, not before.

That took longer than I expected.

Except that they don't. The stub falls off by itself.

What's going on with the forum etiquette instructions? OP got his answer in 3 minutes. Perhaps you need to think about the meaning of forum: "a place, meeting, or medium where ideas and views on a particular issue can be exchanged". Why NOT broaden a discussion to include other information than was at first envisioned? You can stop reading whenever you want.

you are right sir!

that darn lying mother of mine! she told me she chewed it off soon after birth. what a biitch.